hexo-images and hexo-covers plugins (#1414)
hexo-images and hexo-covers plugins (#1414)

* Adding hexo-images

* Adding hexo-covers

Co-authored-by: YoshinoriN <0b14d444c8312d4b3bdc27e6a38609628d4ee1c9@outlook.jp>
hexojs/site,lucianobarauna/dochexo,hexojs/site,lucianobarauna/dochexo,lucianobarauna/dochexo